My plan would be to send my kids to dual language programs. If you're a somewhat native Spanish speaker, you can claim to be Hispanic with a clear conscience. "Hispanic" is, legally speaking (for now), an "ethnicity", not a race, which means it is independent of blood (but apparently race is a "socio-political construct" according to the US Census). People are already doing this, plus the people with one Mexican grandparent or something.

This farcical system can't go on forever as is. Either racial preferences in hiring will be banned under the 14th amendment, or the US will adopt a Brazil-style racial preference system, where they will actually test your blood and have technicians measure the tone of your skin and the shape of your face in order to fit you into a category.

I'm in the same situation.

I've already resigned myself that I must tell him to always check those minority boxes and he may want to consider only using his mother's surname on his resume, instead of the traditional dual surname he legally has (Example: Lopez, instead of Smith Lopez).